U.S. Secretary of State John Kerry talks with Iranian Foreign Minister Mohammad Javad Zarif on May 30, 2015, in Geneva, where talks over Iran’s nuclear program had been taking place. (Susan Walsh/AFP/Getty Images)

Speaking at a retirement service for his childhood rabbi last weekend, Steven Fulop, mayor of Jersey City, surprised the congregation by devoting much of his remarks to ongoing negotiations over a nuclear deal with Iran.

The Democratic mayor laid out five very specific conditions to make any deal with Tehran acceptable.

It was “an unusual step for a Jersey mayor,” the local Jersey Journal newspaper reported, and it marked the first time that Fulop had “ventured into the foreign policy arena.”

Fulop’s “five key points” appeared to have been taken verbatim from a one-page briefing document — “5 Requirements for a Good Deal” — recently distributed by the Washington-based American Israel Public Affairs Committee (AIPAC).

They are: unimpeded access to Iran’s nuclear sites; a full explanation of Iran’s prior efforts to develop a nuclear weapon; sanctions relief only after Iranian compliance; long-term prevention of Iran’s nuclear ambition; and complete dismantlement of all Iranian nuclear infrastructure.

Depending on interpretation, all those demands could potentially exceed the parameters currently being negotiated with Iran by the Obama administration.

The deadline for completing the deal is June 30. With little time left to influence the outcome, opponents and proponents are gearing up to sway public and congressional reaction to the final agreement, which lawmakers will have at least 30 days to review.

AIPAC is “undertaking a major mobilization,” said an AIPAC official who declined to be named. It has been joined in opposition Republican-leaning think tanks and political groups. Other organizations, including the American Jewish Committee, have expressed skepticism that Iran can be trusted and called for thorough congressional review.

J Street, the liberal pro-Israel lobby, is leading the charge on the other side. Along with other ­proponents, it has enlisted ­high-profile former government officials and produced a blizzard of printed and online material to argue that the deal is good for America.

The White House is immersed in its own lobbying effort, particularly in Congress, where a senior administration official tallied more than 200 calls, meetings and hearings since April 2, when the United States and Iran announced a framework for the final agreement.

In a speech late last month at a Washington synagogue, President Obama said he would not sign an agreement that allowed Iran to develop a nuclear weapon. Addressing opposition to an Iran deal by the Israeli government of Prime Minister Benjamin Netanyahu, Obama pledged that “our strategic partnership with Israel will remain, no matter what happens in the days and years ahead.”

Both sides claim the support of American Jews. J Street released a poll this week indicating that 59 percent would support the agreement Obama is trying to hammer out with Tehran, a higher percentage than overall U.S. public support for the deal.

“The numbers just go to show — once again — that pundits and presumed communal representatives are flat-out wrong in assuming American Jews are hawkish on Iran or U.S. policy in the Middle East in general,” J Street President Jeremy Ben-Ami said.

Opponents noted that Treasury Secretary Jack Lew was loudly and repeatedly booed Sunday when he spoke about the Iran negotiations at a New York conference organized by the Jerusalem Post.

The June 30 deadline remains the administration’s immediate goal, a senior official said. “We know it’s going to be tough, we know there’s a lot of work to do, and we know that the Iranians . . . like to bring things down to the wire.” The official spoke on the condition of anonymity under ground rules set by the White House.

But “we’re under no illusions . . . that post-June 30, we’re not going to get some potential ­pushback from the Hill,” the official said. “That’s why we’re spending so much time and effort on the front end” to build public and congressional support.

Many believe the deadline will not be met. “My own view is that it’s highly unlikely,” said Thomas R. Pickering, a former top U.S. diplomat who has met with numerous members of Congress to build support for the agreement.

Seyed Hossein Mousavian, a former Iranian nuclear negotiator close to President Hassan Rouhani, told the Tehran Times this week that talks might be extended an additional one to two months and that it was “more constructive in the long run for negotiators to take the necessary time” to complete complicated annexes that will lay out the specifics of the deal.

Under a legislative compromise reached last month between Obama and lawmakers, Congress agreed not to interfere with the negotiations before the deadline. In exchange, Obama agreed that Congress could have a month to review the final agreement, during which he would not lift long-standing, congressionally imposed sanctions against Iran, regardless of what the negotiated agreement might specify.

If lawmakers do not receive a copy of the agreement and all technical annexes by July 10, their review period increases to 60 days, taking them beyond their summer recess and into the fall session.

In addition to whatever problems an extended review might cause between Iran and the United States and its negotiating partners — Britain, France, Germany, Russia and China — it would also give those opposed to the deal in this country more time to build support for a disapproval vote.

Once it completes its review, Congress has the option, by a simple majority vote, to “disapprove” the agreement and bar the president permanently from lifting statutory sanctions.

Obama has said he would veto any such measure. The White House accepted the compromise confident that a subsequent vote to override a veto would never garner enough Democratic votes to reach the required two-thirds majority in both Republican-controlled chambers.

But opponents are counting on extra time to make their case. “I actually think there’s a fairly ­potent argument out there that for Democrats facing a deal like this, they may grow increasingly skeptical the more they know . . . the more they understand the scale of U.S. concessions to Iran,” said Mark Dubowitz, executive director of the Foundation for Defense of Democracies, who said his organization “supports a deal, it just doesn’t support this emerging deal.”

Dylan Williams, J Street vice president of government affairs, said an initial resolution of disapproval would probably pass, at least in the House. But “the crucial vote is the override of a presidential veto,” he said. “I think if a deal is reached that tracks the terms set forth in the framework, it’s going to be very difficult for those opposed to kill that deal in Congress.”

But William Luers, director of the Iran Project, a high-level group that has long supported negotiations with Iran, was less certain.

A delay of a week or so in completing the deal “is probably doable and I don’t think the Democrats will escape,” Luers said. “If it goes on for another month, or two months, that’s a different order of problem. . . . Then I think the Democrats will not hold the line, and the naysayers . . . will try to start a stampede against it.”

This story has been corrected to reflect the positon of the American Jewish Committee on a potential nuclear agreement with Iran. The organization has expressed skepticism about a deal but has not voiced opposition to the still pending deal